Method and apparatus for breaking electric current in flunet conductors



Sept. 3, 1968 G. MESSNER METHOD AND APPARATUS FOR BREAKING ELECTRICCURRENT IN FLUENT CONDUCTORS 8 Sheets-Sheet 1 Filed May 20, 1966mwmzuczo mwmomzouwo mus; Im mz m EDEN.

mm mm mvzm'on GEORG ME SNER G MESSNER METHOD AND APPARATUS FOR BREAKINGELECTRIC Sept. 3, 1968 CURRENT IN FLUENT CONDUCTORS Filed May 20, 1966 8Sheets-Sheet 2 INVENTOR Sept. 3, 1968 G. MESSNER 3,400,055

METHOD AND APPARATUS FOR BREAKING ELECTRIC CURRENT IN FLUENT CONDUCTORSFiled May 20, 1966 8 Sheets-Sheet INVENTOR GEOR G M ESSNER G. MESSNERMETHOD AND APPARATUS FOR BREAKING ELECTRIC Sept. 3, 1968 CURRENT INFLUENT CONDUCTORS 8 Sheets-Sheet 4 Filed May 20, 1966 S ODIU M B R E A KE R A MALGAM FU EL C E LL IR K INVENTOR G E OR 6 M E SSNER U PP E RCIRCU l T H E A T AMALGAM: p

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msncuin? Sept. 3, 1968 G. MESSNER 3,400,055

METHOD AND APPARATUS FOR BREAKING ELECTRIC CURRENT 1N FLUENT CONDUCTORSFiled May 20, 1966 8 Sheets-Sheet 5 INVENTOR GEORG MES NER Sep 3, 1968G. MESSNER 3,400,055

METHOD AND APPARATUS FOR BREAKING ELECTRIC CURRENT IN FLUENT CONDUCTORSFiled May 20, 1966 8 Sheets-Sheet 6 INVENTOR GEORG M E S NER P 1968 G.MESSNER 3,400,055

METHOD AND APPARATUS FOR BREAKING ELECTRIC CURRENT IN FLUENT CONDUCTORSFiled May 20, 1966 8 Sheets-Sheet '7 III INVENTOR GEORG ME SSNER Sept.3, 1968 G. MESSNER METHOD AND APPARATUS FOR BREAKING ELECTRIC CURRENT INFLUENT CONDUCTORS 8 Sheets-Sheet Filed May 20, 1966 INVENTOR G E ORGIESSNER United States Patent 3,400,055 METHOD AND APPARATUS FOR BREAK-ING ELECTRIC CURRENT IN FLUENT CONDUCTORS Georg Messner, Milan, Italy,assignor to Oronzio de Nora Impianti Elettrochimici, Milan, Italy, acorporation of Italy Continuation-impart of application Ser. No.227,907, Oct. 2, 1962. This application May 20, 1966, Ser. No. 551,734

Claims. (Cl. 204-1) ABSTRACT OF THE DISCLOSURE Describes a method offeeding mercury into and discharging amalgam from a multiple tierbi-polar electrolysis cell in which each tier operates at a differentpotential and in which the mercury feed and amalgam discharge streamsare divided into electrically separated increments to prevent shortcircuits between the separate tiers and the feed streams.

This application is a continuation-in-part of application Ser. No.227,907 filed Oct. 2, 1962, now abandoned.

This invention relates to a method and apparatus for breaking anelectric current carried by a fluent conductor. The invention moreparticularly relates to apparatus used with multiple tier horizontaltype electrolytic cells or fuel cells having a flowing mercury cathodeto break the current to and from the mercury cathode, to therebyinsulate the mercury in each tier from the adjacent tiers which operateat a different voltage.

In the horizontal type mercury cell, as described, for example, inUnited States Patent No. 2,544,138, mercury or mercury amalgam flowsover the cell base from end to end of the cell forming a flowing mercurycathode, the electrolyte occupies the space between the anode surfacesand the cathode and electrolysis of the electrolyte takes place in thegap formed between the anode and the cathode surfaces.

In normal use, the base of the cell over which the mercury cathode flowsis inclined sufficiently to permit the mercury to flow by gravity. Thenormal angle of inclination is about 0.20 to 5.0 from the horizontal.The base may be made of a conductive metal, usually steel, or anon-conductive material. If the base is a non-conductive surface, thebase will have metal inserts to establish electrical contact with themercury.

It is desirable to construct horizontal mercury cells in tiers, that is,one cell superimposed upon another.

In such an arrangement as disclosed herein, the base for the upper cellalso serves as the top for the lower cell, etc. The anodes for the lowercell are attached to the underside of this base. Thus, the superimposedcells are arranged as bi-polar cells wherein the upperside of thedividing base is the cathode contact and the lower side is the anodecontact. In such an arrangement, the cell voltage drop for the differentcells are the same, but the potential above ground for each cell isdifferent. In operating a number of bi-polar cells, there is apossibility of shorts formed by (l) the feed brine streams entering thebipolar elements, (2) the depleted brine streams leaving the bi-polarelements, (3) the mercury streams entering the bi-polar elements and (4)the amalgam streams leaving the bi-polar elements. These shorts betweenthe bipolar elements operating at different voltages result in currentleakages, i.e., energy losses. The amount of current leakage is not aserious problem in the case of the brine streams, because of theelectrical resistance of the brine in the long conduits. However, theconductivity of the mercury and amalgam streams is so high that it posesserious problems such as high current losses, and mechanical damage tocells. The shorts between the mercury streams at different voltagescause arcing and vaporization of the mercury, and thus loss of themercury. For these reasons, it is necessary to take special steps tohandle the mercury and amalgam streams fed to the different tiers of amultiple tier bi-polar cell so as to prevent the above occurrences.

The same problems arise in the use of cells used for the directconversion of chemical energy into electrical energy, known as fuelcells, in which fluent mercury is used in the form of a sodium amalgamand flows through the cells. One type of cell was described in anarticle, Fuel Cells-State of the Art, 1961, by John I. Slaughter, intransactions of the Electrochemical Society, Indianapolis, Ind., May 1,1961. If several such cells are connected as bi-polar cells, it isnecessary to keep the amalgam in each cell electrically separated fromthat in each other cell and any other electrical charge.

It is therefore an object of this invention to provide a method andapparatus for breaking the electrical current in a fluent electricalconductor at the inlet and outlet points of an electrolytic cell.

It is a further object of this invention to provide a method andapparatus for feeding mercury to and withdrawing amalgam from aplurality of mercury electrolytic cells operating at different voltageswhereby short circuits are prevented between the cells operated asbipolar cells at different voltages.

Another object is to provide a method and apparatus for feeding andwithdrawing mercury and mercury amalgam to and from a plurality ofbi-polar electrolytic cells whereby energy losses and mercury losses areprevented.

Another object of this invention is to provide a means and apparatus tobreak the electric current in a stream of mercury being fed as a cathodeto a plurality of hipolar electrolytic cells and for further breakingthe current in the amalgam streams withdrawn from these cells.

A further object is to provide a method and apparatus for electricallyseparating in each cell a stream of mercury amalgam passing through aplurality of electrolytic cells having a different potential in eachcell.

These and other objects of my invention will become apparent as thedescription thereof proceeds.

These objects maybe attained by the use of my invention which comprisesbriefly the use of a special mercury distributor or proportionator atthe inlet side of the bipolar electrolytic cells which operate atdifferent voltages to separate the feed stream into separate streams ofapproximately equal size going to each individual cell, and the use ofseparate circuit breakers whereby the feed stream to each of theseparate cells is broken into a number of electrically separateincrements. The separate streams to the different cells of a muliipletier cell, for example, have no electrical contact with each other, buteach has contact individually with its feed stream as it momentarilysupplies mercury to the individual cells. Thus the mercury distributorhas an electric current breaker between the different cells at the inletthereof.

At the discharge end of the cells, the separate amalgam streams from thecells are fed into a similar current breaker and then may be recombinedinto a single stream going to an amalgam decomposer or may be fed asseparate streams to separate decomposers. The amalgam streams are passedthrough a circuit breaking device which separates each stream into anumber of electrically separate increments before entering the commonstream or before going to separate decomposers, thus also serving as anelectric current breaker between the different cells at the outlet endthereof.

The invention will be more fully understood by reference to the drawingsin which,

FIG. 1 shows one embodiment of a substantially complete multiple tierbi-polar mercury electrolytic cell installation in elevation, showingthe electrolytic cells, amalgam decomposer, mercury distributor, inletand outlet circuit breakers, mercury pump, conduits, etc.

FIG. 2 shows a cross-sectional view in elevation of two superimposedbi-polar mercury electrolytic cells.

FIG. 3 shows a cross-sectional view in elevation of a proportionatingmercury feeder.

FIG. 3A shows an alternate construction for a pro portionating mercuryfeeder.

FIG. 4 shows a cross-sectional plan view taken substaniially along thelines 44 of FIG. 3 of the proportionating mercury feeder.

FIG. 5 shows a broken cross-sectional side view of the proportionatingmercury feeder and of the mercury feed circuit breaker.

FIG. 6 shows a plan view partly in cross-section taken substantiallyalong the lines 6--6 of FIG. 5.

FIG. 6A shows an alternate construction for the mercury feed circuitbreaker of FIGS. 5 and 6.

FIG. 7 shows an alternative form of construction for a mercury feed oramalgam discharge circuit breaker.

FIG. 8 shows a simplified cross-sectional view in elevation of anamalgam fuel cell.

FIG. 9 shows a view in perspective of a combined installation includingmercury amalgam fuel cells, mercury electrolysis cells, inlet and outletcircuit breakers, mercury pump and conduits.

FIG. 10 shows a crosssectional side view of one embodiment of an amalgamdischarge circuit breaker, and

FIG. 11 shows a cross-sectional end view of the amalgarn dischargecircuit breaker shown in FIG. 10.

Referring to FIG. 1, the process for the electrolysis of brine comprisesbriefly feeding brine from the feed brine header 1, through conduits 2,2a and 212, into bi-polar cells 3a and 3b. The depleted brine isdischarged at outlets 4a and 4b into separator 5. Chlorine is separatedin separator 5, and brine flows through conduit 6 to header 7, and backthrough a resaturation system whereas chlorine is discharged throughconduit 8 into header 9. While it is preferred to feed saturated brineinto the lower end of the bi-polar cell units 3a and 3b and removedepleted brine from the upper end of the cells, the brine can be fedinto either end of the cells.

Mercury is fed to cells 3a and 312, by means of pump 10 through conduit11 where it is separated by mercury feed proportionator 12 into separatebut equal streams and passes through conduits 13a and 13b to the mercuryfeed circuit breaker 12a and then through similar conduits 13a and 13bto cells 3a and 3b. Mercury to proportionator 12 which is. in excess ofthe amount required is returned to pump 10 by way of conduit 12b. Thefunction of the proportionator 12 will be described more fully insubsequent paragraphs.

Thus the mercury flows by gravity through the cells whereby the brine iselectrolyzed to produce chlorine and the mercury picks up sodiumbecoming mercury amalgam.

The cells 3a and 3b are preferably inclined about from the horizontal,although any inclination from about 0.16 to 85 may be used. Where thecells are inclined, preferably between 5 and 30, from the horizontal theincreased speed of the mercury flow relative to the electrolyteincreases. the efficiency of the cell. Only two cells or cell tiers 3aand 3b have been shown, however, any number of bi-polar cells in tiers,one on top of the other may be used. My preferred construction is a fivetier cell.

The amalgam is discharged at the lower end of cells 3a and 311 throughconduits 14a and 14b into amalgam discharge circuit breaker 15 where theamalgam from the separate cell tiers is separated into individuallyseparate increments which may be fed into separate decomposers orcombined into a single stream which passes through conduit 16- todecomposer 17 for the streams from all the cell tiers. In thedecomposer, water enters at 18 and is contacted counter currently withthe amalgam to produce hydrogen, discharged by conduit 19 to header 20,and sodium hydroxide, discharged through line 21 to header 22, and themercury substantially freed from sodium is recycled through conduit 22to pump 10 or separate mercury streams from separate decomposers, onefor each cell tier may be recycled to pump 10. In the pump 10 all of themercury is at ground potential and the individual streams feed into thecell tiers. and discharged as amaL gam from the cell tiers must beprovided with circuit breakers at the inlet and outlet ends of the celltiers as each tier operates at a different voltage.

Wash water from header 23 for flushing the cells may be passed throughconduits 24a and 24b and into the lower end of cell tiers 3a and 3b andthrough the amal- ,gam discharge circuit breakers by conduits 25, toflush out the cell tiers 3a and 3b, the mercury feed circuit breaker12a, and the amalgam discharge circuit breaker 15. Discharge wash wateris collected through lines 26, 27, 28, etc. into header 29.

The cells tiers 3a and 3b may be of the type generally referred to ashorizontal mercury cells, having an inclination of about 0.16 to 0.5from the horizontal, however, the cell tiers 3a and 3b-are illustratedas inclined about 15 from the horizontal. Cells having inclinations ofabout 2 to about from the horizontal are referred to as inclined planemercury cells and inclinations of between 5 and 30 are preferred. Myinvention is applicable to either horizontal or inclined plane multipletier mercury cells, in which the tiers operate at different voltagesabove ground.

These cells are superimposed on one another (see FIG. 2) so that acommon partition 30 serves as the base of cell tier 3a and the top ofcell tier 3b. While only two tiers have been illustrated, any number ofstacked tiers may be used.

Plate 30 is steel, nickel clad on its upper side, to form a base overwhich the mercury cathode flows in tier 3a. A rubber coating 31 isprovided on the lower side of plate 30 to insulate the metal fromcorrosion. A similar rubber coating is used on all cell surfaces incontact with brine or chlorine. Anodes 32a are suspended from the lowerside of the top of each cell tier. Thus these anodes are in directconnection with plate 30 there above. Cells mounted in this way are"bi-polar since current passes from positive bus bars 33 through cover30 and anode connectors 32 to the anode plates 32a, then through theelectrolyte in 3a, to the flowing mercury cathode 'and lower plate 30,thence to anodes 32a in cell 3!) and so on to the negative bus bars 34.Thus the cells are connected from the cathode of one cell to the anodeof the succeeding cell and so on. Where multiple tiers are used, thatis, in two, three or more cell units, the current path is the same. Eachcell operates at a different voltage, because of the voltage dropthrough the preceding cell tier, but only one set of positive andnegative bus bar connections are needed for the entire cell stacks. Theanode plates 3211 are preferably perforated or re'cticulated titaniumprovided with a platinum plate on the active surface thereof.

Mercury enters the cells through conduits 13a and 13b into mercury feedboxes 35a and 35b, which extend the entire width of the cells, flowsdown the inclined bases of tiers 3a and 3b into end boxes 36a and 36band out conduits 14a and 1412 as amalgam. Any hydrogen envolved in theend box is vented through outlets 37a and 37b.

A member 35c is provided at the top of each mercury feed box 35a, 35b,etc. The members 350 extend substantially over the entire width of themercury feed boxes and serve to spread mercury flowing out of the feedboxes and under the spreaders in a uniform layer over the base orcathode plate of each cell tier. The spreaders c are provided with aninsulating layer 35d and are adjustable by means of bolts 35c to adjustthe gap through which the mercury flows on to the top of plates 30.

Brine enters the cells through inlets 38a and 3811 at the lower end ofthe cells and leaves through the chlorine and depleted 'orine outlets39a and 3911 at the upper end of the cell units in the embodimentillustrated. Each cell tier is preferably filled with electrolyte to thelevel of the chlorine and depleted brine outlets 39a and 39b to provideflooded cells with the space between the chlofine and depleted brineoutlets 39a and 39b and the upper edge 3e of each tier serving as a gasrelease space.

Since the bipolar cells operate at different electric potentials it isnecessary to break or insulate the mercury feed stream to and from eachcell unit to prevent short circuiting, and arcing between mercurystreams at different potentials. It is also desirable to providesubstantially the same amount of mercury feed to each tier so that thetiers will operate with substantial uniformity.

In the mercury feed circuit, the mercury proportionator 12 comprises avertically disposed rubber lined cylindrical tank (see FIGS. 4, 5 and6). Mercury conduit 11 carrying the main stream of mercury from pump 10passes upward through the tank 40 along the vertical axis thereof andterminates in an inverted tube 41. Tank 40 is closed by top 42. Forfeeding a two unit bi-polar cell, two separate compartments 43a and 43bare formed in tank 40 by vertical partition 47. Compartments 43a and 43bdischarge at the lower end into conduits 13a and 13b. Partition 47 thusforms two separate compartments 43a and 43!). If more than two celltiers are to be fed, separate compartments of equal size must beprovided for each tier. Excess mercury is pumped through line 11 'andflows back to pump 10 through conduit 12!). (See FIG. 1.) 't

A vertical shaft 48 (see FIG. 3), journaled through the top 42 isfastened to tube 41 at its lower end and to a source of rotative power(not shown) at its upper end.

In operation, mercury delivered by pump 10 through conduit 11 passes outof tube 41 as a steady unbroken stream. Tube 41 is connected to conduit11 by any suitable packed joint 49. Tube 41 is rotated clockwise byshaft 48 so that the mercury stream passes in turn over compartments 43aand 43b, repeatedly.

As the mercury stream passes over compartment 43a, mercury which enterscompartment 43a flows by gravity through conduit 13a and through a starwheel circuit breaker 56 and then to cell tier 3a and the mercury whichenters compartment 43b flows through conduit 13b and a similar starwheel circuit breaker to cell tier 3!). As the compartments 43a and 43bare of equal siZe, substantially equal measured amounts of mercury arefed into each cell tier. When more than two tiers are used, a similarnumber of proportionating compartments of equal size will be used. Thisassures an equal amount of mercury flowing to and through each of thecell tiers. Thus for 'a three unit cell tier the tank 40 would bedivided into three approximately 120 compartments and for a four unitbi-polar cell tier the tank 40 would be divided into four approximately90 compartments, etc.

The compartments 43a and 43b are rubber lined on the inside to avoidrust, which if formed, would enter the cell tiers.

Thus by means of mercury feed proportionator 12, the mercury feed streamis divided into substantially equal amounts for each tier and fedthrough the circuit breaker 56 to the separate cell tiers whilepreventing electrical contact between the mercury in the different celltiers.

FIG. 3A illustrates an alternate construction for the proportionatingmercury feeder 40. In this embodiment, the construction is generally thesame except that the mercury is fed through a stationary U tube 11Awhich is entirely outside the device. The U tube 41, shown in theproportionator of FIG. 3, is replaced by a receptacle 41A having adischarge tube 41B. A shaft 74 is positioned along the vertical axis andattached at its upper end to receptacle 41A, with a rotative power meansat the lower end of the shaft. Thus mercury is fed by U tube 11A toreceptacle 41A which is rotated by shaft 74 and motor 75. Thus dischargetube 41B feeds to the compartments in the same manner as the U tube 41of FIG. 3. The device of FIG. 3A has the advantage that mercury does nothave to pass through a condiu't having a movable, packed joint.

From the proportionator 12 the mercury for each tier flows through astar wheel or other type of circuit breaker 50 (see FIG. 5) whichdivides the mercury stream into a number of individually separateincrements so that the circuit between each increment is broken and thecell tiers, operating at different voltages, may each be fed with aseparate mercury stream and short circuiting back to the proportionatingfeeder 12 prevented. A separate star wheel circuit breaker is providedfor each tier. The star wheels may be mounted on a common horizontalshaft 55 for rotation at a constant speed. From the star wheel feeder 56the mercury flows thorugh conduits 13a and 13b into the separate celltiers. As a similar star wheel circuit breaker is used for the amalgamat the discharge end of the cell tiers, the circuit breaker will bedescribed in greater detail with reference to the amalgam discharge.

After the mercury has passed through cell tiers 3a and 3b, and hasbecome amalgam, it is preferably recombined into a common dischargestream for treatment in a single decomposer 17, or the amalgam streamfrom each tier may be sent to separate decomposers and the separatestreams reunited in the pump reservoir from which the mercury is pumpedfrom pump 10 to the proportionating feeder 12.

The amalgam discharge streams must be kept separated electrically fromeach other to prevent shorts between the mercury streams discharged fromthe different cell tier units operating at different voltages, and afterthe circuit breaker all of the streams may be combined and fed to asingle decomposer or, if a separate decomposer is used for each stream,the separated streams may be fed at a common potential to the separatedecomposers.

In the embodiment of an amalgam circuit breaker illustrated in FIGS. 10and 11 the amalgam from cell tiers 3a and 3b passes out throughdischarge conduits 14a and 14b. In FIG. 10 it may be seen that theamalgam collects in a pool in the end box 36b of tier 3b (and similarlyin end box 36a in tier 3a), from which it flows into the conduits 14aand 14b which enter the amalgam discharge circuit breaker 15 and connectwith enclosed vertical discharge conduits Stla and 5012 respectively.These discharge conduits are located inside the circuit breaker tank 15which is rectangular in transverse cross-section in the same manner ascircuit breaker 12a in PEG. 6 and in side cross-section has a curvedbottom section 15a. A top 51 closes tank 15, and an inlet 25 is providedfor wash water, and an outlet 52 to a mercury condenser. The wash wateris fed continuously and kept at the level L, passing out through outlet60.

Since superimposed cells 3a and 3b are at different heights, and thusalso their discharge conduits 14a and 14b, amalgam conduits 50a and 5611are at different elevations within tank 15 and spaced apart laterally.The amalgam conduits have vertical discharge tubes 53a and 53b, whichare provided with helical descending flights 54a and 541). Thisarrangement provides for steady amalgam discharge in a continuous streamwhich is not broken into separate droplets.

Tank 15 is fitted with a transverse shaft 55 which may be rotated bypower means (not shown) or in any other manner. Shaft 55 carries starwheels 56a and 56b which are positioned on the shaft beneath dischargetubes 53a and 53b respectively (see FIG. 11). Where more than two celltiers are used a separate star wheel for each tier will be mounted onthe shaft 55. The tank 15 and shaft 55 will be elongated to accommodatethe required number of star wheels. The surfaces of each star wheel areinsulated from each other electrically by rubber insulation 57 and thestar wheels are spaced apart along the shaft 55, as illustrated in FIG.11. Each star wheel has eight compartments which are illustrated asnumbers 61 through 68 in FIG. 10. These compartments are also insulatedfrom each other by rubber lining 57. Outlet 59 is provided at the bottomof tank 15 where amalgam flows into conduit 16 and thence to decomposer17 where one decomposer is used for several cell tiers. Where separatedecomposers are used for each cell tier a separating wall 15b (see FIG.6A) is used between each star wheel to separate the amalgam streams fromeach star wheel and separate conduits 59a and 59b convey the amalgamstreams to separate decomposers.

In operation, amalgam from cell tiers 3a and 3b, flows through conduits14a and 14b into discharge conduits 50a and 50b. Here, the amalgamoverflows the top edge of vertical tubes 53a and 53b and travels downspiral flights 54a and 54b. These spiral flights provide a means forletting the amalgam down to a common level from different heights,without a long vertical free drop which would scatter the amalgam, causesplashing and thus possibly defeat the purpose of keeping the differentstreams electrically separated. The amalgam streams are discharged fromspiral flights 54a and 54b into star wheels 56a and 56b respectively.Rotation of the star wheels discharges the amalgam in each compartmentinto the common pool or into separate pools in the bottom of circuitbreaker tank 15. Thus these star wheels effect the two desired types ofelectrical separation.

First, since these star wheels are insulated from one another, amalgamstreams are also electrically insulated and therefore so are thebi-polar cell tiers 3a and 3b. Second, the separation of the commonamalgam pool discharged through outlet 59 or the outlets 59a and fromthe amalgam streams coming from cells 3a and 3b is also effected by thestar wheels. Taking star wheel 56b, for example, the amalgam stream fromspiral flight (see FIG. is separated by the revolution of the Wheelwhereby the amalgam is discharged successively into eight electricallyseparated compartments which pass beneath the amalgam stream during onerevolution. It will be seen (FIG. 10) that when the amalgam stream isfilling compartment 61; compartment 62, already filled is electricallyseparated from chamber 61; and compartment 63, insulated from 61 and 62,is discharging amalgam to the common amalgam pool or to separate poolsfor separate decomposers. Thus, compartment 63 is in electrical contactwith the amalgam pool and decomposer 17, but not with the correspondingelectrolytic cell tier 3b. Star wheel 56:: is simultaneously performingthe same function as star wheel 56b for the amalgam discharge from celltier 3a. Thus, the amalgam stream from cell tier 3a is likewiseseparated from decomposer 17 or from pump 10 in case separatedecomposers are used for each cell tier. It will be seen, therefore,that the amalgam streams from cell tiers 3a and 3b have beenelectrically separated each from the other, and each stream has alsobeen electrically separated between the cell and the common amalgamdecomposer 17 or pump 10. Any number of amalgam streams may be separatedin this manner provided that there is a star wheel and a discharge tubeand well for each stream. Tank and shaft 55 can be elongated laterallyand vertically to the extent necessary to accommodate the number of starwheels corresponding to the number of cell units in the cell stack. Thestar wheel circuit breakers 56 (FIGS. 5 and 6) for the mercury feedoperate in a substantially similar manner.

FIG. 7 shows an alternative construction for the amalgam dischargecircuit breaker. In this embodiment, each star wheel 56 is replaced bycups carried on an endless belt 71 passing over pulleys 72 and 73. Cups70 discharge into a trough 74 which feeds to the common amalgam pool orpump 10. Cups 70 are insulated from each other and the insulatedover-lapping lips 70a break the amalgam stream between each cup. Otherembodiments of circuit breakers may be used.

Thus, this method and apparatus makes it possible to feed mercury to aplurality of bi-polar electrolytic cells while keeping these cellselectrically separated, and to withdraw amalgam from the cells, stillkeeping them electrically separated, and to combine the amalgam streamsinto a common discharge pool electrically separated from said streamsand therefore the bi-polar cells, all of this being accomplished in asimple yet effective manner.

In the embodiment of circuit breaker for feeding mercury into the cells(see FIGS. 5 and 6), the mercury supply from pump 10 is first passed toa mercury proportionator 12, then to a star wheel circuit breaker 56,and then to the individual cell tiers.

Mercury feed proportionator 12 acts solely as a proportionating feederand is not intended to break the current in the mercury feed. Itconsists of a cylindrical vessel 40 and as many compartments 43a, 43b,etc., as there are cell tiers 3. As the tube 41 rotates with uniformspeed over the compartments 43a, 43b, etc., and as these compartmentsare of uniform size, an equal amount of mercury will be fed to eachcompartment. If the amount of mercury to be fed to each cell tier needsto be increased or decreased, the speed of pump 10 may be increased ordecreased or a valve in the bypass line 12b may 'be opened or closed tocontrol the mercury flow.

The mercury from each compartment 43a, 43b, etc., of the proportionator12 flows through conduits 13a, 13b, etc., to star wheel circuit breaker56. Each stream is fed through a tube 153 to a separate star wheel 56.

Circuit breaker 56 is essentially similar to that illustrated in FIG. 6Ahaving a separate outlet 59a, 59b, etc., for each star wheel 56 and adividing wall 15b between the outlets. However, since the mercury isdischarged from all compartments of proportionator 12 at the sameelevation, the inlet tubes 153 feeding the star wheels in circuitbreaker 56 can also be at the same elevation. Thus, spiral flights 54 ofthe amalgam circuit breaker 15 can be eliminated and replaced by tubes153.

It will 'be understood that the invention has been described for usewith two bi-polar cell units solely for purposes of illustration andthat it is not limited thereto but contemplates the use of a pluralityof such cell units.

As described above, the mercury feed proportionator is provided with thenumber of discharge compartments corresponding to the number of cellunits, and the mercuty feed and amalgam discharge circuit breakers areprovided with a corresponding number of star wheels.

Although the invention has been described for use in conjunction withbi-polar horizontal or inclined plane mercury electrolytic cells, itwill be readily apparent that the circuit breakers described are usefulfor any fluent electrical conductor in use in cells under or producingelectric current where it is desired to separate such cells electricallyfrom each other and/ or from the fluent electrical conductor. Thus, as amethod and apparatus for feeding and discharging cells operating atdifferent potential from a common feed source and into a commondischarge, the method and apparatus herein described may be used forelectrolysis cells of various types, for fuel cells and for variousother purposes.

A simplified cross-section of a vertical fuel cell is illustrated inFIG. 8. In this type of cell, a sodium- .mercury amalgam is formed inzone 81 and passed to cell 80 through line 82. Amalgam flows downvertical steel electrode 83 serving as the cathode support. Water entersthe cell at 84 at the base of the cell and the cell electrolyte passesout the top of the cell at 85. Oxygen is fed to the cell on the oppositeside of porous oxygen electrode 86. Oxygen enters at 87 and leaves at88. The amalgam reacts with the water, reducing the sodium content ofthe amalgam and forming sodium hydroxide as the electrolyte which iswithdrawn at 85. Electric potential of about 1.7 volts is developed atthe electrodes and may be utilized. The depleted amalgam collects at thebase of cell 80 and is withdrawn in conduit 89 to pump 90 and returnedby conduit 91 to mixer 81 for addition of more sodium.

A plurality of fuel cells may be connected in a bipolar arrangement toobtain 'a higher voltage. When this is done, each cell produces the samevoltage, but each operates at a different potential above ground. Thus,the feed divider or proportionator 12 and the circuit breakers 15 and 56described are useful here in the same manner as described. In this caseone mixing vessel is used. The amalgam is sent through the divider to amultitude of cells, recombined in a star wheel circuit breaker, then onepump is used to send the amalgam back to the mixing vessel, andrecirculate. Without the proportionator and circuit breaker, a multitudeof mixing tanks and amalgam pumps and lines would be required, i.e., onefor each cell and uniform feed to each cell would still be a problem. Itis, of course, desirable to have a multitude of amalgam fuel cells sothat a high voltage can be developed, since a single cell only develops0.5 to 1.7 volts.

The amalgam from the operation of the mercury cathode electrolytic cellsdescribed above may be used as the feed to fuel cells.

In FIG. 9 it is shown that the amalgam from four mercury cells 3 couldbe sent through a star wheel circuit breaker 15A. In this case, theelectrical circuit is merely broken for each amalgam stream and theamalgam streams are not recombined. To accomplish this, star breaker 15is modified as shown in FIG. 6A, by putting a partition 15b in the basewhich extends above the water level and thus separates the mercury fromeach star wheel. The mercury is withdrawn through separate conduits 59aand 59b to separate fuel cells. For purposes of simplicity, the detaildrawings of the star breaker in FIGS. 5, 6, 6A, and 11 show only twostar wheels for two cells. However, it is obvious that this isextendable to the diagrammatic illustration of FIG. 9 where fourelectrolytic and four fuel cells are shown. The spent amalgam leavingthe lower end of fuel cells 80 is then sent through a similar starbreaker A, then to individual pumps 10 and then back to the electrolyticmercury cells. In this way, the fuel cell is completely isolatedelectrically from the mercury cells. This, of course, is necessary sincethe potential on each mercury cell would be 3.5 to 5.0 volts while thepotential for the fuel cell might be 0.5 to 1.7 volts. In addition, theamalgam in each fuel cell is isolated from that in the other.

Also referring to FIG. 9 it is obvious that the lower star breaker couldoperate as in FIG. 11 to combine all of the streams of mercury, sendthem to one pump which could then send them to a mercury divider whichcould in turn feed the multiplicity of mercury cells. In this way onlyone pump would be necessary for several fuel cells.

The current developed by each fuel cell would be 70 to 90% of that putinto the mercury cell, the remainder due to a loss of currentefficiency.

It will be apparent that any variation of arrangements may be used asdesired, by placing the mercury feed divider or proportionator 12 ormercury circuit breaker 15 or 15A Where required. For example, oneelectrolytic cell 3 could feed into a number of fuel cells 80' by use ofa star breaker 15 and a feed divider 12. A number of cells 3 can feedinto a larger number of fuel cells in the same way.

It will be apparent that the materials of construction for the feedingand separating devices may be any suitable materials as known in theart.

Thus, it will be readily apparent to persons skilled in the art thatvarious changes and modifications may be made in the invention withoutdeparting from the spirit of the disclosure or the scope of the appendedclaims.

What .1 claim is:

1. The improved method of passing multiple continuous streams of fluentelectrical conductive material into, through and out of a plurality oftiered bi-polar electro-chemical cells operated at different potentialsone from the other while maintaining electrical separation of individualstreams of said fluent material going into and out of each of saidtiers, which comprises dividing said feed stream of said fluent materialinto a number of individual electrically separated streams correspondingto the number of tiers of bipolar cells, separating each of saidindividual streams by sequentially charging sai'd streams into a firstseries of electrically separated compartments to form a plurality ofelectrically separated increments, moving said increments rotationallyaround a horizontal axis in a continuous rotational direction so that atleast one increment separates the first-formed increment from thelast-formed increment, sequentially separately discharging each of saidincrements from the compartment in which it was formed into a pool offluent material which is electrically separated from the correspondingpool of said other individual streams, passing the fluent conductivematerial from said pool into and through one of said bi-polar cells,discharging amalgamated fluent conductive material from said bi-polarcell as an electrically separated continuous stream of amalgamatedfluent material, sequentially charging said steram of amalgamatedmaterial into a second series of electrically separated compartments toform a plurality of electrically separated increments, moving saidamalgam increments by continuous rotational movement about a horizontalaxis so that at least one increment separates the first-formed incrementfrom the last-formed increment, and sequentially separately dischargingeach of said increments of amalgamated material from the compartment inwhich it was formed.

2. The method of claim 1 in which the fluent electrical- 1y conductivematerial is mercury and the amalgamated fluent material is a sodiummercury amalgam.

3. The method of claim 1 in which the electrically separated incrementsare V-shaped in cross-section with the base of the V adjacent the axisof rotation.

4. A device for discharging a plurality of amalgam streams from aplurality of tiers of a bi-polar multipletier mercury electrolytic cellWhile maintaining electrical separation of each of said tiers from theother tiers, which comprises a horizontal shaft having a plurality ofstar wheels mounted thereon, one for each of said plurality of streams,each said star wheel being electrically separate from the other starwheels on said shaft, each said star wheel having a plurality ofelectrically separate compartments, each said compartment having aV-shaped cross-section with the base of the V adjacent said horizontalshaft, means to continuously feed each of said plurality of amalgamstreams to one of said star wheels at a point above said star wheel andinto a compartment thereof, and means to rotate said shaft continuouslyin one direction to sequentially form individual electrically separateamalgam increments in said compartments and sequentially discharge eachamalgam increment from its compartment below said star wheels, thenumber of compartments in said star wheels being such that there is onefilled compartment between the receiving compartment and the dischargingcompartment.

5. A device for discharging a plurality of amalgam streams from aplurality of tiers of a bi-polar multipletier mercury electrolytic cellwhile maintaining electrical separation of each of said tiers from theother tiers, which comprises a horizontal shaft having a plurality ofstar wheels mounted thereon, one for each of said plurality of streams,each said star wheel being electrically separate from the other starwheels on said shaft, each said star wheel having at least eightelectrically separate compartments, means to continuously feed each ofsaid plurality of amalgam streams to one of said star wheels at a pointsubstantially vertically above said shaft and into a compartmentthereof, means to rotate said shaft continuously in one direction tosequentially form individual electrically separate amalgam increments insaid compartments and sequentially discharge each amalgam incrementbelow said star wheels.

6. The device of claim in which the electrically separated compartmentsare V-shaped in cross-section with the base V adjacent said horizontalshaft.

7. An apparatus for feeding multiple continuous streams of fluentelectrical conductive material into, through and out of a plurality oftiered bi-polar electrochemical cells operated at different potentialsone from the other while maintaining electrical separation of individualstreams of said fluent material going into and out of each of saidtiers, which comprises means for dividing said feed stream of saidfluent material into a number of individual electrically separatedstreams corresponding to the number of tiers of bi-polar cells, meansfor electrically separating each of said individual streams comprising afirst series of electrically separated compartments to form a pluralityof electrically separated increments of said fluent electricalconductive material, means to move said increments rotationally around ahorizontal axis in a continuous rotational direction so that at leastone increment separates the first-formed increment from the last-formedincrement, means for sequentially separately discharging each of saidincrements from the compartment in which it was formed into a pool offluent material which is electrically separated from the correspondingpool of said other individual streams, means to pass the fluentconductive material from said pool into and through one tier of saidbi-polar cells, means to discharge the amalgamated fluent conductivematerial from each of said bi-polar cell tiers into a second series ofelectrically separated compartments to form a plurality of electricallyseparated increments, means to move said latter amalgam increments bycontinuous rotational movement about a horizontal axis so that at leastone increment separates the first-formed increment from the last-formedincrement, and means to sequentially separately discharge each of saidlatter formed increments of amalgamated material from the compartment inwhich it was formed.

8. The apparatus of claim 7 in which the electrically separatedcompartments consist of compartments in a star wheel.

9. The apparatus of claim 8 in which the electrically separatedcompartments are V-shaped in cross-section.

10. The method of operating a multiple tier diaphragmless bi-polarinclined flowing mercury cathode electrolysis cell having an inclinationof about 2 to from the horizontal, which comprises feeding substantiallysaturated brine to each tier of the cell and removing depleted brine andthe electrolysis gas from each tier of the cell, providing a common mainmercury feed stream for all tiers of the cell, dividing said mainmercury feed stream into separated substantially equal amountscorresponding to the number of tiers of said cell and feeding one saidequal amount into each tier of said cell by dividing the feed stream toeach tier of said cell into a series of electrically separatedincrements, feeding said series of electrically separated incrementscontinuously into a feed box at the head of each cell tier, feedingmercury from the feed boxes into the cell tiers below the top level ofthe mercury in each tier and below the brine in each tier, flowing themercury from said feed boxes along the cathode plate of each tier to theother end of each tier of said cell while imposing the electrolyzingcurrent on the brine and mercury in each tier, passing the electrolyzingcurrent directly through the electrolyte to the mercury on each cathodeplate without the intervention of a diaphragm, removing mercury amalgamfrom the end of each tier opposite said feed boxes and separating theamalgam into a series of electrically separated increments, dischargingthe increments into a common pool, flowing the amalgam from said commonpool into an amalgam decomposer and recycling the mercury recovered fromthe amalgam decomposer to said main mercury feed stream.

References Cited UNITED STATES PATENTS 588,276 8/1897' Kellner 204-220699,414 5/1902 Reed 204-220 938,191 10/1909 Whiting 204-220 2,576,553 11/1951 Andreasen 204-219 2,688,594 9/1954 Oosterman 204-219 2,719,1179/1955 Blue et a1. 204-220 2,849,524 8/1958 Matsuo et al. 204-2202,876,192 3/1959 Wurbs 204-220 HOWARD S. WILLIAMS, Primary Examiner.

T. TUNG, Assistant Examiner.

